Input-output circuit, recording apparatus and reproduction apparatus for digital video signal

Abstract

A video signal input-output circuit and a recording-reproduction apparatus in which a digitally compressed video signal input in packet form can be recorded and reproduced efficiently and in stable fashion. In this apparatus, a clock reference is detected from a packet signal containing the clock reference and a digitally compressed video signal, a time stamp for a packet is generated using a clock signal in phase with the clock reference and added to the particular packet, and the packet signals with the time stamp added thereto are recorded closely to each other in a data storage element such as a magnetic recording medium. At playback, the packet interval is output by being restored to the original length on the basis of the time stamp added to the packet in store.

What is claimed is: 
     
       1. A digital video signal recording and reproduction apparatus for recording and reproducing a digitally compressed video signal on/from a recording medium, comprising:
 a recording circuit which records a digitally compressed video signal on a recording medium, the digitally compressed video signal being an intermitted input signal in the form of fixed length packets, each packet including a time stamp, the time stamp indicating an input timing of said packets; 
 a reproducing circuit which reproduces said digitally compressed video signal recorded on said recording medium; 
 a clock generating circuit which generates a reference clock of a predetermined frequency; and 
 an output circuit which outputs said digitally compressed video signal reproduced b said reproducing circuit at the same timing as when input, by use of said reference clock and said time stamp of each of the packets. 
 
     
     
       2. A digital video signal recording and reproduction apparatus according to  claim 1 , wherein said time stamp represents information indicating the time of transmission of said packet. 
     
     
       3. A digital video signal recording and reproduction apparatus according to  claim 1 , wherein said time stamp indicated in units of a period of a clock signal of a predetermined frequency. 
     
     
       4. A digital video signal recording and reproduction apparatus according to  claim 3 , wherein the frequency of said reference clock is the same as that of said clock signal. 
     
     
       5. A digital video signal recording and reproduction apparatus according to  claim 4 , wherein the frequency of said reference clock and said clock signal is an integer multiple of selected one of the frame frequency and the field frequency of said video signal. 
     
     
       6. A digital video signal recording and reproduction apparatus according to  claim 5 , wherein the frequency of said reference clock and said clock signal is an integer multiple of a common multiple of 30 Hz, 30/1.001 Hz and 25 Hz. 
     
     
       7. A digital video signal recording and reproduction apparatus for recording and reproducing a digitally compressed video signal on/from a recording medium, comprising:
 an input circuit which inputs a digitally compressed video signal, the digitally compressed video signal being an intermitted input signal in the form of fixed length packets, 
 a time stamp adding circuit which adds a time stamp to each packet, the time stamp indicating an input timing of said packets; 
 a recording circuit which records the digitally compressed video signal recorded on the recording medium; 
 a clock generating circuit which generates a reference clock of a predetermined frequency; and 
 an output circuit which outputs the digitally compressed video signal reproduced by said reproducing circuit at the same timing as when input, by use of the reference clock and the time stamp of each of the packets. 
 
     
     
       8. A digital video signal recording and reproduction apparatus according to  claim 7 , wherein said time stamp represents information indicating the time of transmission of said packet. 
     
     
       9. A digital video signal recording and reproduction apparatus according to  claim 7 , wherein said time stamp indicating in units of a period of a clock signal of a predetermined frequency. 
     
     
       10. A digital video signal recording and reproduction apparatus according to  claim 9 , wherein the frequency of said reference clock is the same as that of said clock signal. 
     
     
       11. A digital video signal recording and reproduction apparatus according to  claim 10 , wherein the frequency of said reference clock and said clock signal is an integer multiple of selected one of the frame frequency and the field frequency of said video signal. 
     
     
       12. A digital video signal recording and reproduction apparatus according to  claim 11 , wherein the frequency of said reference clock and said clock signal is an integer multiple of a common multiple of 30 Hz, 30/1.001 Hz and 25 Hz. 
     
     
       13. A digital video signal recording and reproduction apparatus according to  claim 9 , wherein said clock signal is synchronized with the clock reference of said digitally compressed video signal. 
     
     
       14. A digital video signal recording and reproduction apparatus according to  claim 13 , wherein said digitally compressed video signal is MPEG compressed video signal and said clock reference is SCR or PCR. 
     
     
       15. A digital video signal processing apparatus externally of which a recorder/reproducer is connected, for processing a digital video signal, comprising:
 a first input circuit which inputs a digitally compressed video signal, the digitally compressed video signal being an intermittent signal in the form of fixed length packets; 
 a time stamp adding circuit which adds a time stamp to each packet, the time stamp indicating an input timing of said packets; 
 a first output circuit which outputs the digitally compressed video signal having the time stamp added thereto, to said recorder/reproducer; 
 a clock generating circuit which generates a reference clock of a predetermined frequency; and 
 a second output circuit which outputs the digitally compressed video signal reproduced by said recorder/reproducer at the same timing as when input to the first circuit, by use of the reference clock and the time stamp of each of the packets. 
 
     
     
       16. A digital video signal processing apparatus according to  claim 15 , wherein said time stamp represents information indicating the time of transmission of said packet. 
     
     
       17. A digital video signal processing apparatus according to  claim 15 , wherein said time stamp indicated in unites of a period of a clock signal of a predetermined frequency. 
     
     
       18. A digital video signal processing apparatus according to  claim 17 , wherein the frequency of said reference clock is the same as that of said clock signal. 
     
     
       19. A digital video signal processing apparatus according to  claim 18 , wherein the frequency of said reference clock and said clock signal is an integer multiple of selected one of the frame frequency and the field frequency of said video signal. 
     
     
       20. A digital video signal processing apparatus according to  claim 19 , wherein the frequency of said reference clock and said clock signal is an integer multiple of a common multiple of 30 Hz, 30/1.001 Hz and 25 Hz. 
     
     
       21. A digital video signal recording and reproduction method for recording and reproducing a digitally compressed video signal on/from a recording medium, comprising the steps of:
 inputting digitally compressed video signal, the digitally compressed video signal being an intermitted input signal in the form of fixed length packets, 
 adding a time stamp to each packet, the time stamp indicating an input timing of said packets; 
 recording the digitally compressed video signal which is added to the time stamp on a recording medium; 
 reproducing the digitally compressed video signal recorded on the recording medium; 
 generating a reference clock of a predetermined frequency; and 
 outputting the digitally compressed video signal reproduced by said reproducing circuit at the same timing as when input, by use of the reference clock and the time stamp of each of the packets. 
 
     
     
       22. A digital video signal recording and reproduction method according to  claim 21 , wherein said time stamp represents information indicating the time of transmission of said packet. 
     
     
       23. A digital video signal recording and reproduction method according to  claim 21 , wherein said time stamp indicated in units of a period of a clock signal of a predetermined frequency. 
     
     
       24. A digital video signal recording and reproduction method according to  claim 23 , wherein the frequency of said reference clock is the same as that of said clock signal. 
     
     
       25. A digital video signal recording and reproduction method according to  claim 24 , wherein the frequency of said reference clock and said clock signal is an integer multiple of selected one of the frame frequency and the field frequency of said video signal. 
     
     
       26. A digital video signal recording and reproduction method according to  claim 25 , wherein the frequency of said reference clock and said clock signal is an integer multiple of a common multiple of 30 Hz, 30/1.001 Hz and 25 Hz.